A record haul of half a million silver and gold coins from a 17th Century shipwreck may have been found just 40 miles from Land's End, an expert said.
US treasure hunters said the coins, worth an estimated $500m (£253m), were recovered in the Atlantic Ocean.
But Odyssey Marine Exploration, who described it as the largest find of its kind, refused to pinpoint the location.
US coin expert Dr Lane Brunner said there was evidence the shipwreck was lying off the Cornish coast.
Dr Brunner, from the American Numismatic Association, told Five Live there were clues about the location in a statement given to a US federal court in the autumn.
"They told a judge at that point that they had found the wreck of a seventeenth-century merchant ship in the Atlantic Ocean, just outside the English Channel - about 40 miles off Lands' End.
"So all we can do is add two and two together. It would seem logical given the timing and everything that could be the site."
Shipwreck expert and historian Richard Larn said a Dartmouth-based ship called the Merchant Royal sank off the Isles of Scilly in 1641.
It was laden with bullion from Mexico and there is speculation that this is the wreck salvaged by Odyssey.
Mr Larn and his wife Bridget have written more than 30 books on shipwrecks and the sea, including the Shipwreck Index of the British Isles, which was used by the Government's Royal Commission for Historic Monuments to establish the National Maritime Record.
Odyssey said it had kept the location secret because of security and legal reasons.
"The gold coins are almost all dazzling mint state specimens," Odyssey co-founder Greg Stemm said.
The artefacts, including more than 17 tonnes of silver coins plus a few hundred gold coins, have been shipped to the US and are being examined by experts at an undisclosed location.
The mammoth haul was salvaged using a tethered underwater robot.
Odyssey, which used the code name Black Swan, said it expected the wreck to become one of the "most publicised in history".
It said the site was of huge historical importance because of the insight it would offer into seafaring and the social life of the period when the ship sank.
"Our research suggests that there were a number of colonial period shipwrecks that were lost in the area where this site is located, so we are being very cautious about speculating as to the possible identity of the shipwreck," said John Morris, Odyssey's co-founder.
"We have treated this site with kid gloves and the archaeological work done by our team out there is unsurpassed.
"We are thoroughly documenting and recording the site, which we believe will have immense historical significance," he said.
Odyssey said the coins were recovered in international waters, "beyond the legal jurisdiction of any country", and had been legally imported into the US.